Refs #27745 -- Improved test coverage of contrib.contenttypes.

1 files changed, 23 insertions, 1 deletions

diff --git a/tests/contenttypes_tests/test_fields.py b/tests/contenttypes_tests/test_fields.py
index 88de0ec7f2..ce5e244df5 100644
--- a/tests/contenttypes_tests/test_fields.py
+++ b/tests/contenttypes_tests/test_fields.py
@@ -1,8 +1,12 @@
+import json
+
 from django.contrib.contenttypes.fields import GenericForeignKey
 from django.db import models
-from django.test import SimpleTestCase
+from django.test import SimpleTestCase, TestCase
 from django.test.utils import isolate_apps
 
+from .models import Answer, Question
+
 
 @isolate_apps('contenttypes_tests')
 class GenericForeignKeyTests(SimpleTestCase):
@@ -11,3 +15,21 @@ class GenericForeignKeyTests(SimpleTestCase):
         class Model(models.Model):
             field = GenericForeignKey()
         self.assertEqual(str(Model.field), 'contenttypes_tests.Model.field')
+
+    def test_get_content_type_no_arguments(self):
+        with self.assertRaisesMessage(Exception, 'Impossible arguments to GFK.get_content_type!'):
+            Answer.question.get_content_type()
+
+    def test_incorrect_get_prefetch_queryset_arguments(self):
+        with self.assertRaisesMessage(ValueError, "Custom queryset can't be used for this lookup."):
+            Answer.question.get_prefetch_queryset(Answer.objects.all(), Answer.objects.all())
+
+
+class GenericRelationTests(TestCase):
+
+    def test_value_to_string(self):
+        question = Question.objects.create(text='test')
+        answer1 = Answer.objects.create(question=question)
+        answer2 = Answer.objects.create(question=question)
+        result = json.loads(Question.answer_set.field.value_to_string(question))
+        self.assertCountEqual(result, [answer1.pk, answer2.pk])